I've been encountering an issue the last couple of months where, randomly on my phone, my SIM will just stop being recognized as being in my phone and will display as having no service, and no ability to call or receive phone calls or text via SMS or RCS, however Signal still works when this happens. I've had to manually restart my phone in order to (temporarily) fix the issue, but then it just starts happening again eventually. I've tried replacing my SIM card entirely with a new physical one (I don't use an eSIM), removing and reinserting the SIM tray, cleaning the SIM card itself and the SIM tray, and resetting my mobile network settings. None of these have permanently fixed the issue that I'm having.

I'd have to assume at this point that it's possibly one of two things: either some severe undiagnosed software bug with GrapheneOS, or the physical SIM mechanism on my device is going bad somehow so I'm going to have to switch to just using an eSIM or get it repaired.

r134a Yes, and I just finished flashing stock and restoring the basics of whatever I backed up from GrapheneOS. So far everything is good but it hasn't been long enough yet. I'm going to try running stock for a week, maybe more or less, and see if I still encounter the issue. I'll try and reply with an answer later on if I have an update.

      • r134a

        • Post #4

        Hackneyed Just out of curiosity, not that it would have a big value, but is there like a frequence of this issue u could describe? Like once every few days, once per day, several times per day, etc? Or not really possible and completely random? Also, what device do u have?

            r134a Initially it seemed like the issue only occurred every few days, maybe even less, so it seemed like it would go away on its own. But then in the last couple of weeks it seems more like every couple days to every day. I don't recall doing anything on GrapheneOS or to my phone that could've caused the increased frequency, either. Also my phone model is the Google Pixel 8 Pro, the model should be included in the thread's tags.

                • r134a

                  • Post #6

                  Hackneyed Hardware failure tends to have this characteristics sometimes, either failing completely instantly or getting worse progressivly. Allthough just speculation, i guess being on stock for some time will tell.

                  Also, probably unrelated as u mention your sim isn't recognized when u can't make/receive calls and sms, but worth a shot; is by any chance under your prefered network setting under your sim-settings '4g only'? This could lead to being unable to receive/make calls/sms in certain cases. Allthough this wouldn't make your sim unrecognized...

                      r134a I used GrapheneOS's "LTE-only mode" that is exclusive to their operating system, disabling 5G and also 3G, 2G, etc. However, I've used that mode for the past year or more since I first got the Google Pixel 8 Pro and basically immediately flashed GrapheneOS on it, since I knew about the project beforehand, and I never encountered any issues until recently. Also it wasn't just that I couldn't call or text people, it was like I didn't have a SIM in at all, displaying "no service" and also displaying a message in Google Messages that said "Please insert a SIM card" whenever I tried to text someone. Also if someone tried to call me instead, it would go straight to voicemail, from what I've been told.

                          • r134a

                            • Post #8

                            Hackneyed i've also had an issue 'recently' where i couldn't make calls and received ones would directly go to voicemail. I can't remember though if there was a mention of 'no signal', i don't think so. I don't use google messages so i also don't had the 'please insert sim'. In my case i had also 4g only, but for some reason, probably maintenance or something, the towers in my neighborhood didn't allow 4g calling and probably told the phone to downgrade to 3g, which my phone rejected since i told it to do so with that setting.

                            Though unlikely since in my case, 4g was unavailable for a day or 3. So a restart of the phone wouldn't affect this in any way and make it work again.

                            Might be a relevant read: https://discuss.grapheneos.org/d/18400-telephony-defunct

                            IF it seems however that after some time on stock, the issue is not reoccuring, and u revert back to GrapheneOS, u might want to test it with not 'LTE only', before pointing it to a potential bug.

                            Perhaps it is possible on stock aswell to test this '4g only' and for example 'prefer 4g' (which wouldn't reject a downgrade to 3g if 4g not available), but im not sure?

                                r134a In my case i had also 4g only, but for some reason, probably maintenance or something, the towers in my neighborhood didn't allow 4g calling and probably told the phone to downgrade to 3g, which my phone rejected since i told it to do so with that setting.

                                3G support shut down where I live, before I even had GrapheneOS. So it wouldn't be able to downgrade at all to 3G because there isn't even 3G with basically any mobile carrier (or any MVNO that utilizes their networks). The only options are 4G LTE and 5G basically. My 4G LTE signal is usually pretty reliable, while 5G is technically "better" but it's a newer technology and in the GrapheneOS's "Usage" section mentioning "LTE-only mode" it mentions it as disabling "bleeding edge code" versus the "legacy code" of 3G, 2G, etc. Now, I'm not sure after all this time with 5G being out in my area that the "bleeding edge code" matters much at all and honestly I'm curious if "LTE-only mode" is redundant at this point for anybody living in a country that has had 5G for a long enough time for day zero/one bugs or vulnerabilities to be squashed relating to 5G.

                                r134a Perhaps it is possible on stock aswell to test this '4g only' and for example 'prefer 4g' (which wouldn't reject a downgrade to 3g if 4g not available), but im not sure?

                                On the stock Pixel operating system, you can choose a "Preferred network type" which is kind of like "LTE-only mode" except it isn't actually "LTE-only" but rather tells the phone to prefer 4G LTE or whichever network type you prefer (if I select 3G or 2G it just defaults to LTE instead), and if that doesn't work, use 5G (the only other option for me I guess). In the time I've been on stock I haven't had a single issue yet relating to the SIM not being recognized, so eventually when I go back (assuming this keeps up and there's no issues on stock), I might try what you said:

                                r134a IF it seems however that after some time on stock, the issue is not reoccuring, and u revert back to GrapheneOS, u might want to test it with not 'LTE only', before pointing it to a potential bug.

                                and just try not having it set to "LTE-only" and see if my mobile carrier just hates me and wants me to use 5G (or have it enabled) otherwise it just flat out doesn't work consistently. However I haven't gotten a single notice (text message from my carrier) of an outage related to 4G LTE (usually if there's something wrong they'll at least send a text referring to maintenance occurring), and I was using "LTE-only mode" for basically a year before I even had any issues with the feature, so maybe my carrier changed something related to their cell towers in the past couple of months that negatively effects users using the "LTE-only mode" on GrapheneOS. I use a major cell phone carrier though, so you'd think hundreds of GrapheneOS users would complain of such a problem, not just @Ppoo and me, so maybe it's just the cell towers in my local area?

                                If somehow that doesn't work, the only other option is that it's a GrapheneOS bug unrelated to the "LTE-only mode", which has only affected two people (that have made a post about it). I'm not even sure how I would report that honestly.

                                      r134a Never mind, issue solved, disregard my previous reply. It's a hardware issue on my end, likely just the physical SIM tray failing completely. Thank you for the help though. Converted my physical SIM to an eSIM on stock and then I'm going to switch back over to GrapheneOS. I'm not sure how to add the "solved" tag to the thread myself otherwise I would.

                                        • r134a

                                          • Post #11

                                          That's unfortunate, especially for a pretty recent device! You're welcome and thanks for reporting back.

                                            13 days later

                                            r134a Update: The issue is happening again, I may have been a bit too eager to assume that it was a hardware issue. If it is, it doesn't haven't anything to do with the physical SIM tray I guess.

                                            It's been a couple weeks and at this point I've switched back to GrapheneOS, and an eSIM. For a little over a week, everything seemed fine, but again recently, the issue has been happening again. So I've tried a few things to see if I can narrow it down at least:

                                            • Switching from LTE-Only mode to just 5G (Recommended) or LTE

                                            • Enabling some toggles I had disabled beforehand like "Allow 2G"

                                            • Enabling cellular networks along with Wi-Fi, since before (at home) I would just use Wi-Fi with airplane mode so it wouldn't contact cell towers when I didn't need to

                                            None of these things have worked, I'm likely going to need a developer to help me, or someone that perhaps I can send logs to, since I don't exactly see any other way.

                                            I did however see an interesting tidbit on GrapheneOS's usage guide under their "Carrier Functionality" section, which reads:

                                            • USA users only: You may need to request your carrier to enable CDMA-less mode if you have issues.

                                            I am a "USA user", so I'm curious if this would work. However, I use T-Mobile, and I'm curious why there hasn't been any reports otherwise from anybody else, especially issues coming from a major cellular carrier, about the issue I've been having if it's really an issue with the carrier.

                                                • r134a

                                                  • Post #15

                                                  Hackneyed Unfortunate to hear the issue is still occuring, even with an esim. If i did understand correctly, the issue wasn't occuring on stock with esim in a period of a week more or less?

                                                  Then u reverted back to grapheneOS, and recently the issue reoccured with esim? Did it appaer after a week? Frequently now or just random?

                                                  It might still be a hardware issue though, perhaps with the baseband modem (speculation)?

                                                  I'll hope indeed a developer can chime in and perhaps assist u in obtaining logs, perhaps these logs could contain data about for example the baseband modem failing (if the system can even catch that) , or point to something. I myself can't really add much anymore which would be of value. Maybe a developer or someone from the US could tell u if the issue u are experiencing would fit on cases where they would advice 'CDMA-less' as u brought up.

                                                      r134a If i did understand correctly, the issue wasn't occuring on stock with esim in a period of a week more or less?

                                                      I haven't tested it on stock specifically on an eSIM. When I converted over to an eSIM, I switched over to GrapheneOS basically immediately afterwards, thinking that I fixed the issue anyways.

                                                      r134a Then u reverted back to grapheneOS, and recently the issue reoccured with esim? Did it appaer after a week? Frequently now or just random?

                                                      The issue itself appeared again after switching back to GrapheneOS, being on it for a week or so with an eSIM (again, thinking it was the physical SIM that was the problem), and then it seemed to start happening again. Also it happens frequently.

                                                      r134a I'll hope indeed a developer can chime in and perhaps assist u in obtaining logs, perhaps these logs could contain data about for example the baseband modem failing (if the system can even catch that) , or point to something. I myself can't really add much anymore which would be of value.

                                                      Unfortunately I'm not exactly sure how common it is for developers to respond on the forum since it seems like perhaps they'd be more active in the Matrix server instead (quote from GrapheneOS's website: "The developers are active on the Matrix room but the broader community can usually answer most questions, and this allows the developers to focus their time and energy on the project.") If a developer, project manager, or someone who works directly with GrapheneOS could explain to me what I should do next (you're the only person that's replied to this thread, but I think some mods have added and removed the "Solved" tag, could be a bot though), I'd be happy to oblige. Thank you for all your help though. I have a very unique, frustrating issue clearly.

                                                      I do have one more thing I'm doing though before I complain on the Matrix server, and that is disabling the "Always-on VPN" toggle. I use a VPN pretty much 24/7, always on, and it didn't occur to me until recently that a VPN could be problematic possibly. I got inspired because whenever I reset my "Mobile Network" settings, it also for some reason resets my VPN configuration, so that gave me an idea to maybe fiddle with that too. So far nothing has gone wrong, but it's too early to tell.

                                                              Hackneyed I haven't tested it on stock specifically on an eSIM. When I converted over to an eSIM, I switched over to GrapheneOS basically immediately afterwards, thinking that I fixed the issue anyways.

                                                              Well this probably will sound repetetive, and very unconveniant, but this basicly means that the potentional factor that it could be a hardware issue still undecided. Probably not what u want to hear, but it might be beneficial to ensure in a way that factor is known.

                                                              I'm not sure someone related to GrapheneOS will read through logs without rulling that big potentional cause out, since it is still unclear wether this issue is caused by using GrapheneOS specifically.

                                                              It would highly suprise me VPN config would have anything to do with this, i even think the 'part' u have issues with on your system bypasses vpn completely. Then again i'm not an expert on Android.

                                                              But your approach to try and do some 'problem solving' does no harm, and perhaps might be the right direction, i don't know. After all that's what i also was trying to do through this thread, trying to problem solve and potentionally point it in the right direction, by first ruling things out. As of now, one of the most feasible causes is still not ruled out.
                                                              I can imagine this is a high inconveniance, especially if after the process it would seem the issue is only occuring on GrapheneOS, but unfortunatly this is the only way since this potentional cause that it might be a hardware issue, is as of now the most likely.

                                                                Hackneyed I do have one more thing I'm doing though before I complain on the Matrix server [...]

                                                                I recommend against complaining as such -- in general, but especially in this case. As you mentioned, whatever is going on is pretty rare. If there were a general problem with T-Mobile in the U.S. on Pixel 8 Pro devices, I think there would be a lot of complaints!

                                                                So, while there might be some odd software problem, the possibility of a hardware problem must be seriously considered, because that is very plausible in a general sense and because it would be consistent with the current extremely small set of reports (right now: just one).

                                                                Perhaps a developer might find evidence in the system log of complaints about the cellular modem.

                                                                It might be good to keep a log of exactly when these outages happen, so it would be possible to compare the longest time between outages on GrapheneOS versus the amount of time running Google's stock OS. For example, if it's possible to go five to ten days on GrapheneOS without an outage, and the device was running the stock OS for only fourteen days without an outage, that might just have been luck.

                                                                  17 days later

                                                                  I have a similiar sim failure and stumpeled upon this thread in search of answers. I will try to investigate on my side and report back.

                                                                  Similar issue here.

                                                                  Pixel 7 Pro with one pSIM and one eSIM. The latter was installed yesterday. Didn’t really test anything at that moment but rebooted the device after eSIM install.

                                                                  This AM I was using the USB port for both file transfer from thumb drive and also with the hardware key; obviously not at the same time. I noticed that at least one of the SIMs disappeared from the Info Bar at the top of the screen. I can’t say for sure if it was the drive or key but removing the device(s) coincided with the SIM re-populating to the Info Bar. This was using one of the alt-Profiles (non-Owner).

                                                                  I did attempt to recreate the issue and was unsuccessful. I will continue to monitor the situation and update this as necessary. I’ll be using the same items tomorrow AM as well.

                                                                  Hope this helps, or affirms such issues are possible. To be clear, I am not suggesting a definitive culprit; GOS, drive, key or Pixel.